# US 11,993,678 B2 · Polyamic acid, polyamic acid solution, polyimide, polyimide film, laminate and flexible device, and method for producing polyimide film

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- Number: US 11,993,678 B2
- Document ID: US11993678B2
- Status: Granted
- Kind: B2
- Application number: 17/039,383
- Filed: 2020-09-30
- Published: 2021-01-28
- Granted: 2024-05-28
- Earliest claimed: 2018-03-30
- Assignees: Kaneka Corporation
- Applicants: Kaneka Corporation
- Inventors: Mari Uno
- Web page: https://patentgrep.com/patent/US11993678B2

## CPC

- C08G 73/1014: {in the form of (mono)anhydrid}
- B32B 27/08: of synthetic resin
- B32B 27/281: {comprising polyimides}
- C08G 73/1032: {characterised by the solvent(s) used}
- C08G 73/1067: {Wholly aromatic polyimides, i.e. having both tetracarboxylic and diamino moieties aromatically bound}
- C08J 5/18: Manufacture of films or sheets
- C08K 5/3445: Five-membered rings
- C08L 79/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- H05B 33/02: Details
- H05K 1/03: Use of materials for the substrate
- H10D 86/411: {characterised by materials, geometry or structure of the substrates}
- H10D 86/60: wherein the TFTs are in active matrices
- C08J 2379/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A polyamic acid that is a polyaddition reaction product of a diamine and a tetracarboxylic dianhydrides, according to one or more embodiments of the present invention. The polyamic acid contains 2′-bistrifluoromethylbenzidine as a diamine component in addition to 3,3′,4,4′-biphenyltetracarboxylic dianhydride and 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride as tetracarboxylic dianhydride components. The polyamic acid may include 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride in an amount ranging from 0.5 mol % or more to 10 mol % or less based on total amount of the tetracarboxylic anhydride.

## Claims

### Claim 1

A polyamic acid which is a polyaddition reaction product of a diamine and a tetracarboxylic dianhydride,
wherein:
the diamine comprises 2,2′-bistrifluoromethylbenzidine,
the tetracarboxylic dianhydride comprises 3,3′,4,4′-biphenyltetracarboxylic dianhydride and 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride,
the 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride is comprised in an amount of 0.5 mol % or more and 10 mol % or less based on a total amount of the tetracarboxylic anhydride, and
an amount of the 2,2′-bistrifluoromethylbenzidine based on a total amount of the diamine is 90 mol % or more.

### Claim 2

A polyamic acid which is a polyaddition reaction product of a diamine and a tetracarboxylic dianhydride,
wherein:
the diamine comprises 2,2′-bistrifluoromethylbenzidine,
the tetracarboxylic dianhydride comprises 3,3′,4,4′-biphenyltetracarboxylic dianhydride and 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride,
the 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride is comprised in an amount of 0.5 mol % or more and 10 mol % or less based on a total amount of the tetracarboxylic anhydride,
the tetracarboxylic dianhydride further comprises pyromellitic anhydride, and
the pyromellitic anhydride is comprised in an amount of 10 mol % or more and 50 mol % or less based on the total amount of the tetracarboxylic anhydrides.

### Claim 3 (depends on 2)

A polyamic acid solution comprising:
the polyamic acid according to claim 2; and
an organic solvent.

### Claim 4 (depends on 3)

The polyamic acid solution according to claim 3, further comprising an imidazole compound.

### Claim 5 (depends on 4)

The polyamic acid solution according to claim 4,
wherein a content of the imidazole compound is 0.10 mole or less based on 1 mole of an amide group of the polyamic acid.

### Claim 6

A polyimide which is a polycondensation reaction product of a diamine and tetracarboxylic dianhydride,
wherein:
the diamine comprises 2,2′-bistrifluoromethylbenzidine,
the tetracarboxylic dianhydride comprises 3,3′,4,4′-biphenyltetracarboxylic dianhydride, and 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride,
the 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride is comprised in an amount of 0.5 mol % or more and 10 mol % or less based on a total amount of the tetracarboxylic anhydrides, and
an amount of the 2,2′-bistrifluoromethylbenzidine based on a total amount of the diamine is 90 mol % or more.

### Claim 7

A polyimide which is a polycondensation reaction product of a diamine and tetracarboxylic dianhydride,
wherein:
the diamine comprises 2,2′-bistrifluoromethylbenzidine,
the tetracarboxylic dianhydride comprises 3,3′,4,4′-biphenyltetracarboxylic dianhydride, and 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride,
the 9,9′-(3,4′-dicarboxyphenyl)fluorenic dianhydride is comprised in an amount of 0.5 mol % or more and 10 mol % or less based on a total amount of the tetracarboxylic anhydrides,
the tetracarboxylic dianhydride further comprises pyromellitic anhydride, and
the pyromellitic anhydride is comprised in an amount of 10 mol % or more and 50 mol % or less based on the total amount of the tetracarboxylic anhydrides.

### Claim 8 (depends on 7)

A polyimide film comprising the polyimide according to claim 7.

### Claim 9 (depends on 8)

The polyimide film according to claim 8,
wherein the polyimide film has a glass transition temperature of 380° C. or higher, and
wherein the polyimide film has a coefficient of thermal expansion during heating from 100° C. to 400° C. of 100 ppm/K or less.

### Claim 10 (depends on 8)

The polyimide film according to claim 8,
wherein the polyimide film has a light transmittance at a wavelength of 450 nm of 75% or more, and
wherein the polyimide film has a haze of 1.2% or less.

### Claim 11 (depends on 8)

A laminate comprising:
a base substrate, wherein the polyimide film according to claim 8 is disposed on the base substrate.

### Claim 12 (depends on 8)

A flexible device comprising:
the polyimide film according to claim 8; and
an electronic element disposed on the polyimide film.

### Claim 13 (depends on 3)

A method for producing a polyimide film comprising:
coating a base substrate with the polyamic acid solution according to claim 3 to form a laminate in which a film-shaped polyamic acid is disposed on the base substrate; and
heating the laminate to imidize the polyamic acid.

### Claim 14 (depends on 13)

The method for producing the polyimide film according to claim 13,
wherein the laminate is heated at a temperature in a range of 380° C. or higher and 500° C. or lower for an amount of time ranging from 10 minutes or more to 60 minutes or less.

### Claim 15 (depends on 13)

A method for producing a polyimide film comprising:
forming the polyimide film by the method according to claim 13; and
peeling the base substrate and the polyimide film from each other.

### Claim 16 (depends on 15)

The method for producing the polyimide film according to claim 15,
wherein the base substrate and the polyimide film are peeled from each other by laser irradiation.